Polgolla Barrage


The Polgolla Barrage is a barrage built across the Mahaweli River at Polgolla, in the Central Province of Sri Lanka. The main purpose of the barrage is to maintain the water level of Mahaweli river at a constant height to provide a uniform potential head at the intake to the underground tunnel which conveys water to Ukuwela powerplant.
The barrage is situated at the upstream edge of the Victoria reservoir, where half of the downstream side of the barrage submerge in the Victoria reservoir when it reaches full capacity. Inundation of the barrage itself reaches the downstream edge of Warathenna - Hakkinda Environmental Protection Area.

Power station

Water from the Polgolla Reservoir is conveyed to the Ukuwela Power Station at, near Ukuwela, via an long underground trans-basin tunnel at a rate of. The power station at Ukuwela consists of two hydroelectric generators, totalling the plant capacity to. Both units were commissioned in July 1976.
The discharge waters of the Ukuwela power station also contributes to several mini hydro powerplants.

Irrigation

Water from the power station is discharged into the Sudu Ganga, which feeds cultivations along itself and then feed Bowatanna Reservoir. The downstream of Bowatanna reservoir is called Amban River, a major tributary to the Mahaweli River, which then connects back to the Mahaweli River at a distance of approximately downstream of the Polgolla Barrage.

Surrounding

Polgolla Reservoir Waterdrome operates a short distance upstream on the inundation created by the barrage. Paranaganthota, a historical river crossing is also situated about 50m upstream of the barrage. The inundation of the barrage facilitates water extraction to the Greater Kandy Water Treatment Plant at Katugasthota which provides drinking water to Kandy.